The present invention relates to shower drains, such as are often used in residential, commercial, and institutional shower constructions.
Typical tiled showers must by code and design have a slope that moves the water from all floor surfaces to the drain. A normal shower configuration would be a square, rectangle, or a polygon. Those configurations mandate four or more triangular shaped quadrants all converging at the drain. Modern day designs have mandated larger overall size showers and more complex base configurations. The larger the shower foot print, the longer the slope. However, these configurations cause problems as noted below.
Each sector of these polygons creates an intersecting plane that creates problems for the setting of tile on the base. Even with small tile or stone (2″×2″), these changes in plane make the finished floor show these changes in plane, which can be aesthetically unacceptable and further can lead to leak problems at lines of intersection. For example, historically the drain is most often placed at the common vertex of these polygons. With the design world trending to larger format tile, the setting of tile with intersecting planes creates a virtually impossible situation for the tile setter due the changes in plane. In addition, many designs go to single slabs of stone for the shower base. This creates a problem for the installation since all drains are designed to be parallel to the subfloor.
A trench drain at the outboard side of one of the peripheral sides of the configuration can solve this problem. It is still necessary to provide the appropriate slope as listed in the plumbing code. However, since the intersecting planes have been eliminated, the size tile used as a finished surface is now not a factor. This opens up the options in both the design and materials that can be used.
Trench drains have been used in outdoor applications by the construction industry for many years. The most common usage is slab on grade applications, such as at the edge of parking lots and building entrances. These applications do not require 100% leak integrity since the ground fill surrounding the drain absorbs any leakage that occurs. These type trench drains are typically manufactured in a variety of linear processes in plastic and various metals. The drain is cut and assembled in sections with end caps at the ends of a run.
While the concept for shower trench drains is similar, the requirement that the installation be 100% waterproof is mandated by code. Since the vast majority of applications are over occupied space, the watertight integrity of the drain system is critical and flood testing is required by most plumbing codes.
There are some existing trench drains for buildings. Most are constructed of variety of grades of stainless steel, and include drain bodies constructed from combinations of cut segments welded together or stampings with additionally welded components. Due to the large number of sizes required by the design community, the ability to build multiple size dies for the drain bodies is not cost effective. Thus, components in known existing trench drain configurations are typically welded. However, welding is expensive and can lead to leak problems. For example, many times welding is the cause for small undetectable leaks that lead to water problems in the field that will not be noticed for many years, at a time when they have already created considerable problems such as rotted under-floor structures and smells associated with wet moldy environments. Notably, leaks can occur at the welds either at the time of manufacture, or during or after installation. These leaks can increase over time (or show up for a first time), due to corrosion and/or stress during installation and/or fatigue and/or from material stress caused in part by the welding. Quality control of welding is difficult, time consuming, and can add considerably to manufacturing expense, particularly where the welding extends 360 degrees around a pipe or connection. It is noted that shower trench drains are unforgiving, in that the water being drained away will find all leaks, and will eventually cause a problem.
Additionally, most known shower trench drains have trench bodies that are made of sheet metal formed with multi-angled surfaces, making them difficult to accurately position during an installation. Specifically, every trench body must have a specific slope for adequate water drainage. The mandated slope in the trench body (with constant wall thickness) leaves a bottom of the drain body on an angle to the drain opening. This occurs since the sheet material of known trench bodies has a uniform constant wall thickness. This factor leads to difficult installations since the drain body needs to be supported by dry packed mortar (or adjustable jacks that are left in the mortar bed) at a perfect sloped angle. It is not easy to form dry packed mortar at a perfect sloped angle, as required to support the known shower trench drain bodies. Molded trench drains also have a similar problem. Specifically, trench drains that are molded from thermoplastic materials effectively have the same issues since constant-thickness wall design is a typical requirement for injected molded designs.
Known existing trench drains are commonly constructed in straight length configurations from 24 to 72 inches. Whether the drain is made from metal or plastic material, the costs to tool the numerous sizes is often cost prohibitive. Complex configurations other than straight are generally too complex to fabricate in metal, except by welding as noted above, since their low volume manufacture makes it cost prohibitive to invest in expensive capital-intensive tooling.